Russian President Vladimir Putin has signed a decree simplifying the procedure for people living in parts of eastern Ukraine held by Russia-backed separatists to obtain Russian citizenship.

The decree was published on the Kremlin website on April 24, drawing a swift and angry response from Ukraine, as well as criticism from the West.

Ukraine's foreign minister called it 'aggression and interference' and a Western diplomat told RFE/RL it was a 'highly provocative step' that would undermine the situation in the war-ravaged region known as the Donbas.

The order and its timing seemed designed to put pressure on Kyiv just three days after Ukraine elected a new president, opening the door to potential changes in a relationship severely damaged for the past five years by Russia's seizure of Crimea and support for the forces who hold parts of the Donetsk and Luhansk provinces in eastern Ukraine.

The decree says its goal is 'to protect human and civil rights' and that the move was 'based on universal principles and norms of the international law.'

Putin aide Vladislav Surkov called it 'extremely important' and said that Russia was carrying out its 'duty to Russian-speaking and Russian-thinking people who have found themselves in a very grave situation' due to what he called 'the repressive actions of the Kyiv regime.'

The decree is likely to spark concerns that Moscow might hand passports to large numbers of people in the war-ravaged regions and then use their status in the Kremlin's eyes as Russian citizens as justification for military action or other steps if Putin and his government want to raise the stakes in their standoff with Kyiv and the West in the future.

Shortly after it was published, Ukrainian Foreign Minister Pavlo Klimkin tweeted that 'Russia's decision to issue passports in the occupied Ukrainian territories is the continuation of aggression and interference in our internal affairs,' adding: 'This is a new 'passport' stage of the occupation of the Donbas.'

Speaking on condition of anonymity because of the sensitivity of the subject, a Western diplomat involved in negotiations related to the conflict in eastern Ukraine told RFE/RL that Putin's decree is 'a highly provocative step that undermines efforts to deescalate the situation' in the Donbas.

According to the decree, permanent residents of 'certain districts of Ukraine's Donetsk and Luhansk regions' wording apparently referring to the areas held by the Russia-backed separatists, which includes the two provincial capitals -- 'have the right to apply for citizenship of the Russian Federation [and obtain it] in a simplified way.'

With reporting by RFE/RL correspondent Christopher Miller in Kyiv, Reuters, TASS, and RBK